Lesson on Black malts

[WestMichBrewer]

A few weeks ago I brewed my first Lager.
I chose Vienna Lager from Brewing Classic Styles.
I entered and scaled the recipe down to 4 gallons in Brewer's Friend.
It called for ~1.6 oz of Carafa II special (de-husked) to give it some color.
When I got to my LHBS, they didn't have that grain in bulk, just the 1 lb bags.
I didn't want that so looked for some subs. Doing some quick math in my head, I went with 3 oz. of Carafa I (not de-husked) thinking it might come close in color contribution.
Brew day went great, fermentation went according to plan, etc.
First taste - First, I am excited that I have made a good lager here , however...
The thing that sticks out is a roasty taste that I wasn't expecting.
Gotta be the substitute Carafa I. I didn't think it would make that much difference, but in an otherwise smooth clean beer, that extra roastiness sticks out like a sore thumb.

Note: 3 oz of Carafa I is not a good sub for 1.6 oz De-husked Carafa II in a Vienna Lager - unless you like yours slightly more roasty.

 

[IslandLizard]

Sorry to hear about your unfortunate lesson.
The color/Lovibond of Carafa I is only about 25% lower than Carafa II. So (almost) doubling the amount will make it stand out more.

Also I think using darker roasts gets more color and lower flavor compared to using higher amounts of lighter roasts, which gives you relatively more flavor and less color.

I agree, aside from color there's a roastiness contribution that may or may not be to your liking. The dehusked variety is less bitter and smoother, even more so when steeped outside the mash and by adding the black liquor after flameout (@180°F), so it never gets boiled. You may want to try that next time.

Aging may mute or blend out some of the upfront roasty flavors you don't like, but who knows where it goes? You could brew a new batch with less, none or a different roast, and blend the 2 to your liking. I know that's a 6-8 week commitment.

 

[IslandLizard]

Speaking of Vienna Lagers...

One of the best Vienna Lagers I've had is Blue Point's Toasted Lager. Another one is Devils Backbone's Vienna Lager. They're on par, but with a slightly different take, making each unique. If you can dig up a good and close clone recipe for either or both of those, they're worth the journey.

 

[chickypad]

You probably would have been okay with the 3 oz of special carafa I (dehusked) but sounds like you got regular. Carafa I and II are really more similar to chocolate malts, with Carafa III being a sub for black malt.

 

[WestMichBrewer]

You probably would have been okay with the 3 oz of special carafa I (dehusked) but sounds like you got regular. Carafa I and II are really more similar to chocolate malts, with Carafa III being a sub for black malt.

Yes, totally my fault for not researching the Carafas better.
"How different can they be?"